MATH 9
unit 3.3  subtracting rational numbers
what do we need to know?
Adding fractions 0f equal and different denominators
Adding decimals
Converting mixed numbers to fractions
Adding mixed numbers
Adding decimals
Converting mixed numbers to fractions
Adding mixed numbers
class notes
9_unit_1.3__subtracting_rational_numbers.pdf  
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more information
the subtraction of integers
"Adding the opposite"
Because adding and subtracting are "inverse" operations, we can convert any subtraction operation into an addition. And because adding is much more ""straight forward", changing a subtraction to an addition could make doing the operation much easier.
Even though we have only applied this. method when dealing with integers, you can "add the opposite" when dealing with the subtraction of all other rational numbers (fractions, decimals, and mixed numbers).
subtracting fractions
The adding and subtracting of fractions are bound by the same rules, which themselves follow the rules of signs for the addition and subtraction of integers:
 When adding and subtracting fractions, your primary goal is to find a COMMON DENOMINATOR.
 Once both fractions have been modified and have the same denominator: THE DENOMINATOR does NOT change, and the numerators are subtracted. (whether you add the opposite or not).
 When adding and subtracting fractions, your primary goal is to find a COMMON DENOMINATOR.
 Once both fractions have been modified and have the same denominator: THE DENOMINATOR does NOT change, and the numerators are subtracted. (whether you add the opposite or not).
An alternate method: THE BUTTERFLY METHOD
thebutterflymethodforaddingafractionswithdifferentdominators.pdf  
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subtracting decimals
Just like when adding decimals, when adding in a vertical fashion, the decimal point MUST be lined up. Then, you subtract from left to right:
subtracting mixed numbers
videos that can help you
INTERACTIVE ONLINE ACTIVITIES
worksheets







Review  workbook
workbook__unit_3.3.pdf  
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